Section 7.2
Using the Law of Universal Gravitation
Practice Test
1.
What is the orbital period for the satellite pictured in Figure 7-10?
a.
0.052 h
b.
1.6 h
c.
3.1 h
d.
170 h
Hint
2.
When Uranus was discovered, why didn't Newton's law of gravitation correctly predict its orbit?
a.
Uranus was being attracted by the planet Neptune.
b.
Newton's law of gravitation applies only to objects on Earth.
c.
The period of Uranus was not known at the time.
d.
Newton's law could not be applied over such great distances.
Hint
3.
If you weigh 440.0 N on Earth's surface, how much would you weigh on the planet Mars? Mars has a mass of 6.42×10
23
kg and a radius of 3.40×10
6
m.
a.
557 N
b.
1.4×10
3
N
c.
235 N
d.
165 N
Hint
4.
A satellite orbits Earth 375 km above its surface. What is its speed in orbit?
a.
7.61 × 10
3
m/s
b.
7.68 × 10
3
m/s
c.
7.61 × 10
3
m/s
2
d.
7.68 × 10
3
m/s
2
Hint
5.
The __________ of an object is measured by applying a force to the object and measuring its acceleration.
a.
inertial mass
b.
resistance
c.
gravitational mass
d.
weight
Hint
6.
If Earth began to shrink but its mass remained the same, what would happen to the value of
g
on Earth's surface?
a.
It would remain constant.
b.
It would decrease.
c.
It would be halved.
d.
It would increase.
Hint
7.
A satellite orbits Earth 5.00×10
2
km above its surface. What is its speed in orbit?
a.
7.90×10
3
m/s
b.
7.61×10
3
m/s
c.
7.76×10
3
m/s
d.
5.92×10
3
m/s
Hint
8.
A satellite orbits Earth 5.00×10
2
km above its surface. What is its period?
a.
15.7 h
b.
1.58 h
c.
1.43 h
d.
94.6 h
Hint
9.
If you weigh 500.0 N on Earth's surface, how much would you weigh on the planet Jupiter? Jupiter has a mass of 1.90×10
27
kg and a radius of 71.5×10
6
m.
a.
1.24×10
4
N
b.
1.26 N
c.
126 N
d.
1270 N
Hint
10.
A satellite orbits Earth 375 km above its surface. What is its period?
a.
1.54 h
b.
92.1 h
c.
55.3 h
d.
16.0 h
Hint
11.
If the satellite in Figure 7-10 were to remain above the same point on Earth, what would its orbital radius have to be changed to?
a.
2.2×10
11
m
b.
1.7×10
11
m
c.
1.3×10
11
m
d.
1.1×10
11
m
Hint
